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Re: Origin of feathers



On May 6th, TomHopp said:

>>..the razorbill incubates its one large egg on a cliff ledge by   
wrapping one wing around it.  The bobwhite quail lays so many eggs that   
it is forced to "clutch" them with its wings in order to keep the   
outermost ones from cooling.  The jacaranda, incredibly, picks up its   
eggs under its wings and walks across lilly pads with them.<<

I think these examples of modern birds using wing feathers to assist with   
incubation strengthen the case a bit; more so than previous examples of   
flapping birds that use wings to assist with brooding chicks. (I assume   
the name "jacaranda" is a reference to one of the species of _Jacana_   
 --the plover-like birds with the huge feet that walk on floating   
vegetation?)

>>Particularly, it is good to bear in mind that most modern birds have   
relatively huge breasts.  It is not surprising that they use these to   
cover and warm their eggs/young.  Oviraptor was not so well endowed and   
seems, as you point out, to be showing a novel behavior.  One might call   
it, "how to incubate when you haven't yet evolved a large breast."<<

Your point about the relatively small breastbone of Oviraptor is a good   
one. It certainly suggests that flightless nesting theropods may have had   
novel incubation behaviours; and perhaps using wing feathers was it.  But   
modern ratites and other flightless birds with reduced breastbones   
incubate without using wing feathers (picture a Penguin, or a Kiwi.)  And   
your examples of modern "wing incubators" are all flappers, presumably   
with relatively larger breastbones. Hmmmm.

Fascinating idea, though. You'd think that with all those fossilized   
Oviraptor nests in China, they could find at least one feather......